An FDC structure of special-shaped aluminum

Abstract

This invention relates to the field of flexible die-cut circuit board technology, and discloses an irregularly shaped aluminum FDC structure, including an irregularly shaped FDC body and multiple connecting components. The FDC body includes a pure aluminum foil plate, two cover films, and two adhesive layers. The two ends of the pure aluminum foil plate in the thickness direction are respectively connected to the cover films through the two adhesive layers. Multiple connecting components are respectively disposed on the body, with their ends extending to the outside of the body and used for soldering to the battery cell. This application solves the problem of high cost in battery cell integration in related technologies through the above technical solution.

Description

Technical Field

[0001] This invention relates to the field of flexible die-cut circuit board technology, and more particularly to an irregularly shaped aluminum FDC structure. Background Technology

[0002] FDC (Flexible Die-Cut Circuit Board) is an electrical connection component primarily used in battery packs of new energy vehicles or energy storage systems. Its core function is to integrate series and parallel battery cells, along with necessary insulation protection structures, into a compact whole, replacing traditional, scattered wiring harnesses and connectors. This design not only achieves efficient electrical connections and signal acquisition between battery cells but also simplifies the assembly process, improves the space utilization and energy density of the battery pack, and enhances electrical safety and reliability.

[0003] Currently, traditional FDC consists of copper foil FDC and nickel sheet, which are integrated through laser welding, resulting in high costs. Summary of the Invention

[0004] This application discloses an irregularly shaped aluminum FDC structure to solve the problem of high cost in cell integration in related technologies.

[0005] To solve the above problems, the present invention adopts the following technical solution: This application discloses an irregular aluminum FDC structure, including an irregular FDC body and multiple connecting components. The irregular FDC body includes a pure aluminum foil plate, two cover films and two adhesive layers. The two ends of the pure aluminum foil plate in the thickness direction are respectively connected to the cover films through the two adhesive layers. Multiple connecting components are respectively located on the busbar body, with both ends extending to the outside of the busbar body and used for welding battery cells.

[0006] In some designs, the connecting components include a first welding tab, a second welding tab, and a fuse. The ends of the first welding tab and the second welding tab extend to the outside of the busbar body and are used for welding the battery cells. The first and second welding pieces are connected by a fuse.

[0007] In some solutions, the irregular FDC body has multiple first extension components, which are equidistantly arranged on one side of the irregular FDC body along a first direction, and there are gaps between the two sides of the first extension components and the irregular FDC body. The end of the first extension component extends to the outside of the irregular FDC body, and the first welding piece is connected to the first extension component and is partially located on the outside of the first extension component.

[0008] In some embodiments, the first extension component includes an inclined portion and a horizontal portion, one end of the inclined portion being connected to the irregular FDC body and the other end being connected to the horizontal portion, and the horizontal portion being parallel to the busbar body. The inclined section tilts from the end connected to the irregular FDC body towards the end connected to the horizontal section, towards the top of the irregular FDC body.

[0009] In some embodiments, the first welding piece includes a first welding portion and a first connecting portion, the first connecting portion being disposed within the first extension member and connected to the fuse; The first welded part is located outside the first extended member and is connected to the first connecting part.

[0010] In some designs, the busbar body also has multiple second extension components, which are equidistantly arranged on the other side of the irregular FDC body along the first direction. The end of the second extension component extends toward the top side of the irregular FDC body, and the second welding piece is connected to the second extension component and is partially located on the outside of the second extension component.

[0011] In some embodiments, the second welding piece includes a second welding portion and a second connecting portion. The second connecting portion is disposed on the second extension member, with one end extending to the outside of the second extension member and connected to the second welding portion, and the other end connected to the fuse. The second connecting part has a first bending structure, and the connection position between the second connecting part and the second welding part has a second bending structure.

[0012] In some designs, the first bending structure has a first reinforcing part, and the second extension component has a first through groove corresponding to the first reinforcing part, with the first reinforcing part embedded in the first through groove; And / or, the second bending structure has a second reinforcing part.

[0013] In some designs, the irregularly shaped battery cell integrated busbar also includes a double-sided adhesive layer, which is placed on top of the busbar body.

[0014] In some designs, the irregularly shaped FDC body is provided with multiple through-holes; And / or, the covering film is made of polyethylene terephthalate material.

[0015] The technical solution adopted in this invention can achieve the following beneficial effects: The irregularly shaped aluminum FDC structure of this application directly designs the irregularly shaped FDC body as an aluminum foil FDC structure with pure aluminum foil as the conductive layer and integrated by a cover film and adhesive layer. At the same time, it is equipped with connecting parts that extend to the body to directly weld the battery cells, perfectly replacing the traditional multi-component assembly mode of "copper foil FDC + nickel sheet". This not only eliminates the separate component of nickel sheet and its associated spot welding and assembly processes, thereby significantly reducing processing costs and process complexity, but also replaces copper with aluminum as the main conductive material, greatly saving material costs. This makes the overall structure lighter and thinner with higher integration. While achieving lightweighting, it directly forms a stable aluminum-aluminum welding path, effectively improving the reliability and economy of the internal connection of the battery pack. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 These are isometric views of irregularly shaped FDCs disclosed in some embodiments of this application; Figure 2 This is a top view of the irregular FDC disclosed in some embodiments of this application; Figure 3 yes Figure 2 Enlarged view of point A in the middle; Figure 4 This is an isometric view of the connecting components disclosed in some embodiments of this application; Figure 5 This is a structural diagram of the busbar body disclosed in some embodiments of this application; Figure 6 This is a partial structural schematic diagram of the irregular FDC body disclosed in some embodiments of this application.

[0018] In the picture: 100-Irregular FDC body, 101-First extension component, 1011-Inclined part, 1012-Horizontal part, 102-Second extension component, 103-First through groove, 104-Second through groove, 105-Gap, 110-Pure aluminum foil plate, 120-Adhesive layer, 130-Covering film; 200 - Connecting component, 210 - First welding piece, 211 - First connecting part, 212 - First welding part, 220 - Second welding piece, 221 - Second connecting part, 222 - Second welding part, 223 - First bending structure, 2231 - First reinforcing part, 224 - Second bending structure, 2241 - Second reinforcing part; 300 - Double-sided adhesive layer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] During their research on FDC (Foil-Driven Direct Current) devices, the inventors discovered that the high cost of FDC stemmed from its multi-material, multi-part stacked structure, consisting of copper foil FDC and individual nickel sheets. Firstly, copper foil itself is a precious metal with high costs. Furthermore, to carry large currents and reduce impedance, thicker copper layers are often required, further increasing material costs. Secondly, the nickel sheet, acting as a connector, is an independent component, requiring additional material costs and stamping fees. Its connection to the copper foil must be achieved through laser welding, a precision process that demands significant equipment investment and complex process control, increasing manufacturing costs and time. The entire assembly involves the procurement and processing of two different materials and multiple assembly and welding steps, resulting in low integration and cumbersome production processes. These layered costs in materials, processing, and assembly contribute to the high cost of the final product.

[0022] The following is in conjunction with the appendix Figures 1 to 6 The present application provides a detailed description of an irregular aluminum FDC structure through specific embodiments and application scenarios.

[0023] Some embodiments of this application disclose an irregular aluminum FDC structure, including an irregular FDC body 100, a double-sided adhesive layer 300, and a plurality of connecting components 200.

[0024] like Figure 1 , Figure 2 and Figure 5As shown, the irregular FDC body 100 includes a pure aluminum foil plate 110, two cover films 130 and two adhesive layers 120. The two ends of the pure aluminum foil plate 110 in the thickness direction are respectively connected to the cover film 130 through the two adhesive layers 120.

[0025] The pure aluminum foil 110 serves as the core conductor, replacing the precious metal copper foil, and undertakes the current transmission function while significantly reducing material costs. The upper and lower cover films 130 mainly function as insulation, protection, and define the cell connection point positions through pre-opened windows, replacing the insulation and structural support functions of traditional plastic brackets. The two adhesive layers 120 firmly bond the pure aluminum foil 110 and the cover films 130 into a whole through hot pressing or adhesive bonding, achieving mechanical fixation and electrical isolation. This integrated laminated structure completely replaces the original multi-part assembly mode. Furthermore, by using the lower-cost pure aluminum foil 110 to replace the precious metal copper foil FDC, and utilizing the integrated laminated structure of the cover film 130 and adhesive layers 120, the separate nickel sheet is directly eliminated, thus achieving material simplification and component integration at the source. This not only significantly reduces material costs but also simplifies the manufacturing process by eliminating laser welding processes and reducing assembly steps.

[0026] In this embodiment, the thickness of the pure aluminum foil 110 is preferably 0.2 mm, the adhesive layer 120 is glue, preferably with a thickness of 50 μm, and the cover film 130 is made of polyethylene terephthalate (PET) material, preferably with a thickness of 50 μm.

[0027] The 130 cover film, made of PET material, provides excellent electrical insulation and mechanical protection while also offering advantages in flexibility, heat resistance, and low cost, making it a perfect replacement for traditional bulky plastic supports and thus reducing costs.

[0028] like Figure 1 and Figure 2 As shown, multiple connecting components 200 are respectively disposed on the irregular FDC body 100, with both ends extending to the outside of the irregular FDC body 100 and used for welding the battery cell. The multiple connecting components 200 are conductive structures that are specially extended from the irregular FDC body 100, with both ends directly exposed to the outside so as to be connected to the battery cell by welding. This realizes the integrated molding of the connecting components 200 and the irregular FDC body 100 (i.e., pure aluminum foil plate 110), eliminating the independent nickel sheet part and the complex laser welding process between it and the copper foil in the traditional solution. This simplifies the structure, saves space, significantly reduces material and processing costs, and improves the reliability and production efficiency of the connection interface.

[0029] like Figure 4As shown, the connecting component 200 includes a first welding piece 210, a second welding piece 220, and a fuse. The ends of the first welding piece 210 and the second welding piece 220 extend to the outside of the irregularly shaped FDC body 100 and are used for welding the battery cells. The first welding piece 210 and the second welding piece 220 are connected by the fuse. Under normal operating conditions, the first welding piece 210 and the second welding piece 220 form a continuous electrical path through the intermediate fuse, jointly undertaking the functions of current transmission and structural grounding. When the system experiences extreme faults such as high-voltage short circuits, the fault current will cause the fuse to melt rapidly, thereby actively cutting off the electrical connection between the irregularly shaped FDC body 100 and the external battery cells. By setting up an integrated connecting component 200, the traditional independent nickel sheet and welding process are replaced, simplifying assembly and reducing costs. Furthermore, the built-in fuse provides a fault isolation mechanism to prevent high voltage from entering the low-voltage acquisition system, significantly improving the system safety level of the battery pack.

[0030] like Figure 1 , Figure 2 and Figure 6 As shown, the irregular FDC body 100 has a plurality of first extension members 101. The plurality of first extension members 101 are equidistantly arranged on one side of the irregular FDC body 100 along a first direction, and there are gaps 105 between the two sides of the first extension members 101 and the irregular FDC body 100 respectively. The end of the first extension member 101 extends to the outside of the irregular FDC body 100. The first welding piece 210 is connected to the first extension member 101 and is partially located on the outside of the first extension member 101.

[0031] By designing first extension components 101 with gaps 105 at equal intervals on one side of the irregular FDC body 100, it serves as a transition bridge for welding with external battery cells. The gap 105 design allows the extension components to undergo local deformation when subjected to welding thermal stress or assembly stress, preventing stress from being directly transmitted to the core area of ​​the irregular FDC body 100. The first extension component 101 eliminates the need for traditional independent nickel sheets, simplifying assembly and reducing cost and size. Furthermore, the gap 105 buffers and protects the delicate acquisition lines on the irregular FDC body 100 from damage by welding and installation stress, significantly improving the overall structural reliability and production yield.

[0032] In this embodiment, the first direction is as follows: Figure 1 As shown in L.

[0033] like Figure 6As shown, the first extension component 101 includes an inclined portion 1011 and a horizontal portion 1012. One end of the inclined portion 1011 is connected to the irregular FDC body 100, and the other end is connected to the horizontal portion 1012. The horizontal portion 1012 is parallel to the irregular FDC body 100. The inclined portion 1011 is inclined from the end connected to the irregular FDC body 100 toward the end connected to the horizontal portion 1012 towards the top of the irregular FDC body 100. By designing the first extension component 101 as a three-dimensional structure transitioning from the inclined portion 1011 to the horizontal portion 1012, wherein the inclined portion 1011 extends upward from the irregular FDC body 100, the final welding plane of the horizontal portion 1012 is raised within a limited space, achieving dual optimization of spatial adaptation and stress dissipation. The inclined structure allows the irregularly shaped FDC to span the height difference of structural components or cells inside the battery pack; at the same time, the inclined part 1011 can effectively absorb and buffer the longitudinal and transverse stresses from welding and assembly, avoid stress concentration at the root, protect the irregularly shaped FDC body 100 and precision circuits, and significantly improve space utilization, structural adaptability and long-term reliability.

[0034] Furthermore, the inclined portion 1011, serving as a transitional structure connecting the irregular FDC body 100 and the horizontal portion 1012, essentially forms a continuous structural rib with a specific angle through its upward inclined extension. This design not only physically guides and disperses external welding stress to a larger area of ​​the irregular FDC body 100 via the inclined surface, but also forms a local triangular support system together with the horizontal portion 1012. This significantly enhances the bending stiffness and torsional stability of the irregular FDC body 100 around the connection point, thereby effectively reinforcing the structural stiffness of the pure aluminum foil substrate 110 itself without the need for additional independent supports or thickened materials, and improving the structural integrity of the overall component under vibration, impact, and other operating conditions.

[0035] like Figure 4 As shown, the first welding piece 210 includes a first welding portion 212 and a first connecting portion 211. The first connecting portion 211 is disposed within the first extension member 101 and connected to the fuse; the first welding portion 212 is located outside the first extension member 101 and connected to the first connecting portion 211. The first connecting portion 211 is built into the extension member and is responsible for forming a reliable electrical connection with the fuse; the first welding portion 212 is exposed outside the extension member and is specifically used to support welding with external battery cells. The external first welding portion 212 can withstand the high temperature and mechanical impact during welding, preventing heat and stress from being directly conducted to the built-in first connecting portion 211 and the precision fuse, thereby protecting the performance of critical safety components from the influence of the welding process.

[0036] It should be noted that the first connecting part 211 also has an inclined structure so that the first connecting part 211 is located inside the first extension member 101.

[0037] like Figure 1 , Figure 2 and Figure 6 As shown, the irregular FDC body 100 also has a plurality of second extension members 102, which are equidistantly arranged on the other side of the irregular FDC body 100 along a first direction; the ends of the second extension members 102 extend toward the top side of the irregular FDC body 100, and the second welding piece 220 is connected to the second extension member 102 and is partially located on the outside of the second extension member 102.

[0038] By symmetrically arranging multiple second extension components 102 extending upwards on the other side of the irregular FDC body 100 and integrating them with the second welding piece 220, a balanced electrical connection and mechanical fixing system is formed on both sides. The dual-side extension design makes the force on the irregular FDC body 100 more balanced, significantly improving the overall resistance to torsional loads; at the same time, the equidistant connection points on both sides provide a multi-point stable installation foundation for the irregular FDC, enhancing the structural stability in vibration environments, and making the docking of the irregular FDC with the external battery pack structure (such as the side plate aluminum beam) more convenient and reliable, realizing a higher degree of integration and modular assembly.

[0039] like Figure 4 As shown, the second welding piece 220 includes a second welding portion 222 and a second connecting portion 221. The second connecting portion 221 is disposed on the second extension member 102, with one end extending to the outside of the second extension member 102 and connected to the second welding portion 222, and the other end connected to the fuse.

[0040] The second welding piece 220 employs a partitioned design, embedding the second connecting part 221 within the second extension component 102 and connecting it to the fuse, while the second welding part 222 is exposed to perform welding functions, thus achieving symmetrical electrical isolation and process protection on both sides. This arrangement allows both sides of the irregularly shaped FDC body 100 to connect to the core fuse via independent extension paths. While improving structural symmetry, it ensures that the high temperature and stress generated during welding are strictly limited to the external welding part, effectively isolating the internal fuse from critical circuits. This achieves zero impact on the core safety components during the welding process on both sides, further ensuring the consistency and long-term reliability of the electrical safety functions of the irregularly shaped FDC body 100.

[0041] like Figure 4As shown, the second connecting portion 221 has a first bending structure 223, and the connection position between the second connecting portion 221 and the second welded portion 222 has a second bending structure 224. The first bending structure 223 makes the second connecting portion 221 flexible inside the extended component, which can alleviate the longitudinal stress from the welded portion; the second bending structure 224 forms local elasticity at the weld interface, which can compensate for alignment errors during assembly and buffer lateral stress. The two work together to effectively isolate the transmission of welding thermomechanical stress to the fuse and the irregular FDC body 100, protecting the core electrical connection, and improve the fault tolerance and vibration fatigue resistance of the component during the actual assembly process, thereby enhancing the reliability and adaptability of the overall structure.

[0042] Furthermore, the first through slot 103 achieves localized weight reduction without sacrificing structural strength by precisely removing non-critical load-bearing materials from the second extension component 102, thereby further reducing the overall weight of the irregular FDC body 100 in conjunction with the pure aluminum foil substrate 110.

[0043] like Figure 4 As shown, the first bending structure 223 has a first reinforcing part 2231, and the second extension component 102 has a first through groove 103 corresponding to the first reinforcing part 2231, with the first reinforcing part 2231 embedded in the first through groove 103. The structure of the first reinforcing part 2231 embedded in the first through groove 103 firstly provides a crucial rigid support point for the flexible bending area, effectively preventing excessive deformation or fatigue fracture of the bending structure under stress; secondly, this interlocking design plays a self-positioning role during assembly, ensuring the positional accuracy of the second connecting part 221 in the extension component; finally, it distributes local stress more evenly throughout the overall structure of the second extension component 102, rather than concentrating it at the root of the bend, thereby significantly improving the durability and reliability of the composite structure under long-term vibration and welding thermal cycling.

[0044] like Figure 4 As shown, the second bending structure 224 has a second reinforcing part 2241. The second reinforcing part 2241 directly strengthens the local rigidity of the weld interface, effectively preventing fatigue fracture at the bending point caused by repeated welding thermal stress or vibration, thereby significantly improving the long-term connection reliability of the exposed weld.

[0045] like Figure 1 , Figure 2 and Figure 6As shown, a double-sided adhesive layer 300 is disposed on the top of the irregularly shaped FDC body 100. The double-sided adhesive layer 300 forms a non-structural adhesive interface on the top of the irregularly shaped FDC body 100. Utilizing its pressure-sensitive adhesiveness, the irregularly shaped FDC body 100 is temporarily fixed to adjacent structural components during the battery module assembly stage (FDC station), effectively preventing displacement of the irregularly shaped FDC body 100 during subsequent laser welding or transmission, and ensuring the accuracy of welding alignment. At the same time, this design simplifies tooling, improves the smoothness and efficiency of automated assembly, and avoids the additional weight and stress concentration problems caused by using rigid connectors.

[0046] Specifically, the double-sided adhesive layer 300 is located on the top of the irregular FDC body 100, which is covered by the cover film 130.

[0047] like Figure 6 As shown, the irregular FDC body 100 is provided with multiple through-holes 104. The through-holes 104 not only reduce the weight of the irregular FDC body 100 and improve its flexibility to adapt to installation stress, but also optimize the heat dissipation path of the overall structure through regular layout, which helps to distribute heat evenly, thereby achieving synergistic enhancement in three dimensions: lightweight, reliability and thermal management.

[0048] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0049] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An irregularly shaped aluminum FDC structure, characterized in that, The device includes an irregularly shaped FDC body and multiple connecting components. The irregularly shaped FDC body includes a pure aluminum foil plate, two cover films, and two adhesive layers. The two ends of the pure aluminum foil plate in the thickness direction are respectively connected to the cover films through the two adhesive layers. Multiple connecting components are respectively disposed on the FDC body, with both ends extending to the outside of the body, and are used for welding battery cells.

2. The irregularly shaped aluminum FDC structure according to claim 1, characterized in that, The connecting component includes a first welding tab, a second welding tab, and a fuse. The ends of the first welding tab and the second welding tab extend to the outside of the irregular FDC body and are used for welding the battery cell. The first welding piece and the second welding piece are connected by the fuse.

3. The irregularly shaped aluminum FDC structure according to claim 2, characterized in that, The irregular FDC body has a plurality of first extension components, which are equidistantly arranged on one side of the irregular FDC body along a first direction, and there are gaps between the two sides of the first extension components and the busbar body respectively. The end of the first extension member extends to the outside of the irregular FDC body, and the first welding piece is connected to the first extension member and is partially located on the outside of the first extension member.

4. The irregularly shaped aluminum FDC structure according to claim 3, characterized in that, The first extension component includes an inclined portion and a horizontal portion. One end of the inclined portion is connected to the busbar body, and the other end is connected to the horizontal portion. The horizontal portion is parallel to the busbar body. The inclined portion tilts from one end connected to the busbar body towards the other end connected to the horizontal portion toward the top side of the irregular FDC body.

5. The irregularly shaped aluminum FDC structure according to claim 4, characterized in that, The first welding piece includes a first welding portion and a first connecting portion, the first connecting portion being disposed within the first extension member and connected to the fuse; The first welded portion is located outside the first extension member and is connected to the first connecting portion.

6. The irregularly shaped aluminum FDC structure according to claim 3, characterized in that, The irregular FDC body also has a plurality of second extension components, which are equidistantly arranged on the other side of the busbar body along the first direction. The end of the second extension component extends toward the top side of the irregular FDC body, and the second welding piece is connected to the second extension component and is partially located on the outside of the second extension component.

7. The irregularly shaped aluminum FDC structure according to claim 6, characterized in that, The second welding piece includes a second welding portion and a second connecting portion. The second connecting portion is disposed on the second extension member, with one end extending to the outside of the second extension member and connected to the second welding portion, and the other end connected to the fuse. The second connecting part has a first bending structure, and the connection position between the second connecting part and the second welding part has a second bending structure.

8. The irregularly shaped aluminum FDC structure according to claim 7, characterized in that, The first bending structure has a first reinforcing part, and the second extension component has a first through groove corresponding to the first reinforcing part, with the first reinforcing part embedded in the first through groove; And / or, the second bending structure has a second reinforcing portion.

9. The irregularly shaped aluminum FDC structure according to claim 1, characterized in that, The irregularly shaped FDC body also includes a double-sided adhesive layer, which is disposed on the top of the irregularly shaped FDC body.

10. The irregularly shaped aluminum FDC structure according to claim 1, characterized in that, The busbar body is provided with multiple through-type second slots; And / or, the covering film is made of polyethylene terephthalate material.

Images